Why do caravans overturn

However, your tow car also needs to of sufficient weight to better control the caravan during unstable towing conditions. All these factors and more will be discussed below.

Disclaimer: Hey! By the way… any links on this page that lead to products on Amazon or Caravan Guard are affiliate links and I earn a commission if you make a purchase, with no additional cost to you. Caravan snaking is an unstable towing situation which may ultimately lead to jack-knifing. The main objective of this post is to help avoid caravan snaking in the first place. However, you also need to be prepared and know what to do if your caravan does start to snake on a fast A road or motorway.

So in summary, Frank in the video above provides some important tips and hints. The only point I would personally add is to put your hazard lights on to warn other motorists of the issue.

This will hopefully indicate to other road users they should keep their distance until you have the car and caravan under control. If the caravan starts to snake you should do the following:. One of the most important points is to use engine braking, not the wheel brakes to gently slow down the car and caravan until both are under control. As Frank states in the video, best practice is not to accelerate out of the problem, which I have my self heard referenced before as the solution.

When a caravan is snaking its a form of kinetic energy movement energy. To get the car and caravan under control again that kinetic energy needs to dissipate. If you accelerate or brake, both of those forces are additional sources of kinetic energy which can actually make the situation worse. You will have to adjust the points above on how to stop a caravan snaking for your own specific circumstances.

For instance, if you are driving an automatic, depending on the car, you may not be able to manually select a lower gear to increase engine braking resistance. Also depending on what type of road you are on a safe place to pull over and check the tow car and caravan will also obviously vary. However, my main aim of this post is to help you avoid that situation happing in the first place.

In practice it means the driver will only feel a sway following a severe push but this will immediately be stopped as it returns to the centre of equilibrium. It works without any electronics. It is difficult to diagnose a particular issue such as this without first hand inspection, however,if the caravan had no material change and it occured since the tow vehicle was changed then it would be prudent to check the tow vehicle tyre pressures and front wheel geometry.

The tyres present a slip angle when a side force exists therefore the pressures are critical in that if the pressure is too low for the load the tyre slip angle increases and this can create an imbalance between the front axle tyres and the rears. Almost all modern cars aim for a understeer characteristic exhibited when the front axle tyres have a greater slip angle than the rears so if the the rear tyres are running with pressures too low then the slip angles may be greater than the front and create instability when either cornering or when a side force exists similarly if the geometry is out.

With a trailer this effect is less troublesome, however, it could be a problem if they are running severely flat since the lateral inertia will display some additional sway. If the trailer is balanced with the appropriate nose heavy bias it should not become an uncontrolled sway as long as the speed is below the natural sway frequency.

However, there are many reasons why an uncontrolled sway can commence therefore, the only remedy is a proactive control system to mitigate the immediate danger. Hi There are numerous comments suggesting that grease on the tow ball may be the reason for a snake, it may well contribute when contaminated with a friction hitch, however, I found that the main benefit of using a friction hitch is that it offers more holding security of the coupling and very little towards stability.

The only solution is a Proactive Differential Stability device to stop it before it can start. Hi just got back from our annual tour of France and after miles I was on the M11 heading home when confronted by a foreign artic going slower than my 60 mph so I signaled to pass and proceeded.

In this situation you have to keep your eyes ahead since any side wind can push you into trouble, when I estimated I was clear I checked the mirrors and could not see the truck. I then felt the push and pull of something alongside — the truck had accelerated up my inside and then the suction of the truck and my caravan was pulling us together — I dare not take my eyes off ahead and my wife said he was about 6 inches from the side of us.

I was trying to pull away but with great difficulty — the truck also pulled away onto the hard shoulder and we eventually parted with no contact — phew. The day was saved by my Differential Stability System keeping the combination straight and true at 60 mph with no hint of sway despite a severe avoidance reaction. I designed it to also cope with a jackknife something that no electronic device can do. I will give my caravan with the device fitted Free of charge to any reputable company who can take it to market subject to an agreement and due diligence.

Hi read what Allan Green says: This is an easy one for me to answer since I have found the solution but getting it recognised is like treading sand. I think Allan would take comfort in knowing that he did nothing wrong — it is an inherent problem with trailers that not one company has identified because they concentrate too much on electronic technology before understanding the causes of uncontrolled sway — I have kept my system under wraps to date and I can declare that there is no prior art in the patent applications that apply the simple answer to the problem except mine.

I have done the maths as well as all the trials to perfect it and have been in some very difficult terrain across the Massive Central in France. It employs a powerful hydraulic single damper combined with an innovative mechanical arrangement to apply individual braking to either side when a sway reaches a specific inertia — the key to its success is that it does not use any electronics or motors and applies a correction before a sway can start by applying an equal and opposite force at the centre of equilibrium — that is when the sway returns to the online position and no further after it has been pushed out of line by any wind force at half the sine wave No other device on the market can do this except mine.

It is not affected by speed and sensible loading with a bias to the nose has no affect either. I carry two electric pedal assisted mountain bike on the back of my van and as long as the van is not over loaded and maximum nose weight is on the ball. It does not slow the combination down in operation as some electronic applications do when they cannot discriminate between a bump in the road.

I would invite any competent company to contact me if they are interested in marketing it. The Jeep is rated to tow around kg. The caravans that I am towing would not be more than kg max. The downward hitch weight appears to be well with in the Jeeps limits. At the moment the caravan is with a experienced RV repairer, but up to now he is stumped and does not know what is causing the problem. Does anyone know whether it would be wise to fit a weight distribution device as well as using the AST that is fitted.

If some one out there has any ideas to fix the problem I would be extremely grateful. By the way, before I bought the Jeep I towed the caravan with a 2lt Ssangyong Karando diesel with absolutely no problems at all. Something could have gone wrong of course during the change over. Cheers Dave. Try towing the caravan with a different vehicle to pin down which is causing the problem. It may be that the Jeep has a worn shock absorber or suspension play on one side.

I am a qualified transport engineer with 40 years in the Automotive and transport industry. Most of the comments are hitting the correct buttons, however, some in the wrong order. The route cause of snaking is the wind, it is the same issue that caused the Tacoma bridge to collapse in New York City and many other instances. Today we know how to cure this using designs and spoilers to great effect like on the Millau Bridge in southern France and tall buildings anything else is a sticking plaster.

Before I fitted or activated any passive device I stood my van in a strong wind and placed smoke generators at various point to see where the problem starts. I made up some spoilers to fit in the awning track and played with them until I found the sweet spot — bingo.

Then just as a back up I always have at least one coupling anti-snake — my preferred one is the AL-KO hitch, always fit shock absorbers to the van axles if they are not already on, in addition I have designed, tried and tested a device to dampen vertical bounce between the van and car which also assists the van wheel and hitch dampers to keep the wheels on the ground, I fit car suspension stiffeners to the rear springs to help keep the combination level and load the van to the limit the tow bar allows which leaves a lot to be desired on many at kg — this gives your coupling device the best advantage of stopping the oscillations because there is less leverage for it to cope with.

Always fit TPMS to the caravan tires — they measure temperature and pressure — an absolute must have today. You must remember that any device can only get you out of trouble for that instance and that goes for any active ATC — the problem will start allover in seconds after they have been deployed and released — you cannot possibly carry on on a long journey with ATC switching on and off every time a lorry passes you or the wind is too strong etc. The other thing is do not depend on electronics they do fail and being electrical, blow fuses, jam up and cannot think as quick as you can.

Remember that wind resistance increases at the square of the speed — the magic number is 60 mph in the UK and 58 mph in most of the EU for caravans.

In three thousand miles of travel around France I have not experience any instability. Passing trucks do give a very slight pull together because of the vacuum they create but the combination settles back without any oscillation. One other thing — learn how to check and adjust the Van brakes never rely on the once in a while service — it will also keep you fit.

As a by the way- I fitted dash cams in the van front and rear they are very useful — not just for security — they measure the driving features such as braking and bounce and capture the moment in a separate file — I got masses of data from these. Safe driving to you all. Many thanks for getting in touch. Thanks everyone, noseweight and car rear tyres at higher than normal pressure are the two first steps I will take. Also as a precaution I will change the pressure pads in the alko hitch.

The caravan dealer may have roughed them up with sandpaper or cleaned them with brake fluid but if the previous owner used a greased towball accidentally those pads may still be contaminated. I have often wondered whether using a roof deflector on the car has any beneficial effect on stability? Does anyone know? Do they actually work to improve economy? Hi Robert, Caravans are arguably the most efficient design you can get in terms of fuel saving with the exception of what I put in my long winded post — I would say you will not benefit much from roof mounted deflectors but as I found out — side corner mounted spoilers do reduce snaking if designed and placed in the right spot.

See my post. It is all too easy to let the speed build up after cresting a hill — you have to back off the throttle much more than when solo because you have been using much more power to lug up the hill. My one snaking experience came is similar circumstances — speed build up after cresting a hill and the snaking triggered a panel van going past at about 80mph at the wrong moment. I was inexperienced at the time. It was very scary! Now I have cruise control I use it a lot when towing.

Once you are going too fast downhill, you are in a catch22 situation, because you need to slow down, but lifting off or braking reduces stability because the caravan is pushing the car.

Presumably Andy had a stabiliser e. Alco of some sort? Does the Audi have the towing stability control feature that is activated when the towing electrics are connected? You may need to have a specific towbar installation for it to activate. Certainly he needs to check the noseweight on a new caravan. Plus keep a close watch on speed at all times! I bought a lunar clubman si from a big dealer two days ago and as an experienced caravaner, loaded it carefully.

On two downhill straights snaking happened. My audi avant a4 auto transmission tdi is perfectly matched l think. What I did not have with me was a hitch weight tester. By hand I reckon the hitch may have been quite heavy but I didnt see any car tail sag or nose heavy look to the caravan.

My ideas so far are to add around 6 lbs pressure to the car rear tyres and to check hitch nose weight and try different weights. Has anyone got preferred nose weights or other ideas? And the snaking ocurred reducing downhill speed from 65 to 60mph. Yes I know that I should have been below 60, but speed can creep up on lone downhill runs almost without you noticing.

Many thanks for getting in touch — no doubt that was a scary experience for you. Some of the previous comments about accidents and incidents have frankly horrified me. Whilst I applaud the many suggestions about making sure your outfit is thoroughly prepared beforehand, what would be the best action to take if you then actually find yourself in such a terrifying situation. I would suggest that slamming on the brakes would be just about the worst and most dangerous thing you could possibly do.

If the caravan is swinging wildly to one side or the other at the moment of slamming on the brakes the forward momentum of the caravan could result in it literally trying to overtake your car a jackknife, or worse.

So what could you do to bring your outfit back into your control. May I offer to you a tale of my own experience almost 50 years ago. My towing vehicle was a short wheelbase 10 year old clapped out Land Rover with a cc petrol engine. The steering was so worn that I could move the wheel 50 mm in either direction before the road wheels started to move no exaggeration. There were no stabilisers so, as I was soon to find out, every breath of wind would cause the caravan to snake, moving the back of the Land Rover violently to the left and right.

I had only travelled a mile, literally, into my mile journey and I was so frightened I almost aborted the whole journey. But so much had been invested in time, money, ferry bookings etc. Then I noticed something very interesting. Our book Why Caravans Roll Over — and how to prevent it, explains all.

The major part of it is written in totally clear English. It also has a section that explains the issues in more technical detail. This part is primarily for engineers working in the travel trailer industry and technically-minded readers seeking detailed explanations. It includes many references. In essence, Why Caravans Roll Over — and how to prevent it, explains just why travel trailers may jack-knife and roll over It shows to assess the stability of your own tow vehicle and travel trailer — and how to fix any issues.

Collyn Rivers is a semi-retired automobile research engineer. He is the author of seven books, five of which are about making RVs and solar work optimally. Prices for the paperback version including delivery can vary dramatically.

RVBooks recommends you shop around. We've included a number of reputable booksellers you may wish to consider. Just ask. ISBN: If you own a camper van or motor home, you'll want this book. The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above. Battery charging quickly and deeply by a generator is very possible but onl I see 4X4 drivers who cars have a higher centre of gravity getting into problems.

Also Vans loaded with gear riding at strange angles whilst the car has a couple with virtually nothing in the car. If the car and van do nor sit level when you start off. Forget it! And why the heck do the police not stop caravans that are obviously badly loaded? Vans are fine with wait low down, but those who drive heavy 4X4 cars and think they are bullet proof. Beware that higher centre of gravity.

It's not so much the higher centre of gravity of 4x4's that's at fault but the fact that they usually have high aspect ratio tyres their sidewalls are relatively high compared to the tread width.

Especially if the tyres are of the all-terrain type with soft sidewalls, they have less lateral stiffness, making the car sensitive to sideways forces from the caravan. Mar 14, 3, 0 0. Lutz is certainly correct re the tyres on a 4x4 - I have AT's All Terrains and due to the high side wall you do get "lag" in the steering responce compared to the rubber band type tyres you see on modern performance cars that give superb "feel" and directional stability.

I need the AT's as I do have to drive off-road in all weathers. I just drive accordingly when towing on the road. The most accurate reason why caravans turnover that I have read on this Forum?? If you plan correctly, drive within your abilities and those of your outfit you should not have a problem. Tho' it must be said that there are many other wheels out there with nuts behind them - so caution rather than blind faith in what you are doing is probably best.

Aug 26, 31 0 0. Deborah, Simple answer to prevent this happening. Get on a caravan towing course offered by the Caravan Club among others. You must log in or register to reply here. Post thread. Lost keys Started by Ken and June 5 minutes ago Replies: 0. Rememberance Day! Cost of fuel Started by Buckman Oct 27, Replies: Tow Cars. New Member Introductions. Weather Started by Beachball Apr 6, Replies: Latest posts.

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